Fiat 1996 Brava Service Manual page 274

Bravo-Brava | p
98 range
lev
Engine
Fuel system
10.
ENGINE RPM AND TDC SENSOR
The engine rpm and TDC sensor (1) is fixed
to the cylinder block/crankcase and is facing
the flywheel on the crankshaft pulley.
Operating principle
The sensor consists of a tubular casing (1)
containing a permanent magnet (3) and an
electrical w i n d i n g (2). As a result of passing
the flywheel teeth, the magnetic f l o w pro­
duced by the magnet (3) oscillations accord­
ing to the variation in the gap.
These oscillations create an electro-motive
force in the w i n d i n g (2) producing an alter­
nately positive voltage (tooth facing the sen­
sor) and negative voltage (gap facing the
sensor). The peak sensor output voltage d e ­
pends, all other factors being equal, on the
distance between the sensor and the t o o t h
(gap).
I
3 2 B -
I
_ n
-JT_
1 2
1
3
i
22B
Wiring connector
The sensor resistance can be measured by
disconnecting the connector and connecting
and ohmmeter to the sensor.
Resistance: 9600+10% ohm at 20 C
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